The modern Gregorian calendar cannot be used to calculate the true seventh-day Sabbath because it lacks one very vital feature of Biblical time-measurement: lunar months. The Creator’s calendar begins each month with the New Moon. Because the weekly cycle restarts with every New Moon, it appears that the Sabbath “floats” through the Gregorian week. In reality, it is the Gregorian months that float through the very consistent format of the lunar months.

Creator's Calendar